The present embodiments relate to medical diagnostic ultrasound. In particular, ultrasound is used to characterize tissue.
Important pathological information may be obtained by characterizing the ultrasound attenuation of tissue. The level of attenuation may be a biomarker for fatty liver disease. Cancers, such as breast cancer, may be diagnosed, in part, based on attenuation of ultrasound.
Attenuation may be measured using spectral analysis of radio frequency backscatter signals. A change in amplitude of power spectra as a function of depth of the acoustic backscatter indicates the attenuation. These backscatter approaches may suffer from variability, even with spectral averaging.
U.S. Pat. No. 9,244,169 teaches a technique to measure attenuation using acoustic radiation force impulses (ARFIs). ARFIs at different frequencies are transmitted, and attenuation is estimated from displacements responsive to the ARFIs. Use of multiple ARFIs may result in inaccuracies due to motion. Focusing effects may also contribute to inaccuracy.